Various tapping machines and apparatuses have been developed for drilling or cutting a hole or opening into fluid containing pipe or vessel. Those skilled in the art know that this technique is called hot-tapping. The purpose of hot-tapping is to tap into a pipe or other fluid vessel that is still acting as a fluid conduit so that the fluid supplied in the pipe does not need to be cut off. Thus, hot-tapping enables users to tap into a pipe or fluid conduit to obtain access to the fluid without disrupting the fluid supply. Several issued U.S. patents discuss hot-tapping, including U.S. Pat. No. 6,321,778 (“Chen”), U.S. Pat. No. 6,640,827 (“McClure”), and U.S. Pat. No. 6,648,562 (“Calkins”). These patents are incorporated herein by reference in their entireties as if fully set forth below.
Typically hot-tapping devices are connected or coupled to a tapping valve. Tapping valves are usually welded, clamped or otherwise mounted or attached to an outer wall of the pipe or vessel, such as it shown and discussed in McClure. A machine or apparatus housing is connected to a tapping valve, often with the use of a special adapter. To drill a hole in a pipe, the tapping valve should be open so that a drilling tool can be advanced toward a pipe, as shown and discussed in Chen and Calkins. Once the drilling tool is in place, the drilling operation can be initiated to cut a hole in the wall of the pipe or fluid conduit to gain access to fluid (gas or liquid) located within the interior of the pipe or fluid conduit.
Conventional pipe tapping devices generally have a feed screw to advance the drilling tool in the tapping valve toward the pipe and continuously through the drilling operation. Total traveling length required for the feed screw to complete drilling operation, depends on pipe diameter, valve height, and saddle height. For a typical medium size pipe this traveling length may reach significant numbers. For example, total traveling length required to conduct a drilling/tapping operation on a 12″ pipe is approximately 20″ to approximately 22″ (depending on the valve and saddle dimensions). Considering that conventional feed screws have threads with a small pitch (8-14 threads per inch), the total number of the feed nut rotations to advance the feed screw may reach approximately 160-308 rotations for the above 12″ pipe.
As a result of the large number of feed nut rotations, tapping pipe with conventional pipe tapping devices requires significant time. At the same time, just a small portion of the required traveling, approximately 20% relates directly to the drilling operation. Whereas, the other 80% of traveling is required to move the drilling tool through the tapping valve and saddle up into contact with a pipe's outer surface wall.
Some conventional devices have attempted to address this problem, but still currently have drawbacks. For example, “The TapMate™ Pipe Drilling Machine” by TRANSMATE (a Division of Romac Industries, Inc.) is one conventional device. The TapMate device utilizes an accelerated movement of a drilling tool through a tapping valve and a saddle by using two telescoping square tubes: brake and thrust. These tubes slide one inside of the other to provide quick travel. The brake tube has a metal brake shoe to lock the tubes together before tapping. After tapping is finished, the brake shoe must be unlocked to retract the thrust tube. At this moment, however, the boring bar providing rotational force to the drilling tool is under pipeline pressure, and loosening the brake nuts may lead to jumping or rapid movement of the thrust tube, potentially causing very serious injury. It may be very dangerous to a person conducting tapping, considering that axial force, applied to the tube, may reach several hundred pounds, depending on line pressure and boring bore diameter. Indeed, the TapMate Owners Manual recommends loosening the brake nuts while standing to the side of machine to avoid injury from pressure pushing back on the bar.
What is needed, therefore, is a pipe tapping apparatus, system, and method that reduces the overall time for tapping a pipe in light of the large ratio of feed nut turns to travel distance needed to place the drilling tool in contact with a pipe. What is also needed is a pipe tapping apparatus, system, and method that can be effectively used without causing harm to a user by providing sufficient protection from the effects of high pressure fluid within a pipe or other fluid conduit.